Pump/Flow Rate Help

kristic · Apr 9, 2023

We are setting up our new Red Sea 425 GT and we are adding a Vectra S2 pump. We have everything plumbed in and turned on and running but it’s loud. How do you determine the flow rate? I know the maximum is 1400 but it it proportional? It’s like we can hear the water rushing through the system and it’s so loud it’s difficult to watch tv over it. This can’t be right. Any help?

Mr. Mojo Rising · Apr 9, 2023

I don't have that kind of pump or tank, hopefully this will bump and someone can help.

If your pump is a dc pump, then you can adjust the power, it doesn't need to be at max power. Get yourself another powerhead to create the flow in the tank, don't rely on the return line as the main flow of the tank.

You should be able to close the valve a little on the main drain. If its wide open, it creates that loud gurgling sound from water rushing down too fast, so partially close the valve.

Pistondog · Apr 9, 2023

kristic said:
We are setting up our new Red Sea 425 GT and we are adding a Vectra S2 pump. We have everything plumbed in and turned on and running but it’s loud. How do you determine the flow rate? I know the maximum is 1400 but it it proportional? It’s like we can hear the water rushing through the system and it’s so loud it’s difficult to watch tv over it. This can’t be right. Any help?

Sounds like the drain is not siphoning properly ir theres gurgling.
What kind of drain does the tank have?

TheBear78 · Apr 9, 2023

With the head height and restrictions it's going to be nearer 1100 gph at full speed which is still a little over the recommended flow rate for the 425. It could be possible but would probably need more water in the system.
Have you tried slowing rhe pump or adjusting the valve at all?
I'm not sure what your experience is but typically your desired flow should be set by the pump and the drain valve adjusted to suit.
It sounds like it's probably overflowing through the emergency drain and this could be alleviated by opening the valve a little assuming you are happy with the flow rate.
Also, if you're just running socks (not a Reefmat) the water flowing into them can be noisy. I've put filter floss on top of mine to stop the trickle.

metalle · Apr 9, 2023

Few things, noise is typically from the suction side (slurping). If you try to run at max you may see it from vortex suctioning air if not enough head pressure for the flow(NPSHR). Throttle back or increase suction head. On the discharge side, larger the pipe diameter the better, as for the same volume the fluid speed is lower and less noise. Minimize discharge restrictions (elbows or reducers) to avoid head pressure losses. See S2 pump curve below